Nice article. It has to be read very carefully. It is cutting edge but something 99% of pond owners can't do (effectively manage the N/P ratio to produce optimum good plankton blooms).

The reason pond fertilizers are high in P and not N is based on years of water chemistry science and reality. Most non-productive ponds (those that need added fertility) have low to no P and it is the limiting nutrient factor. Without adding P no or minimal blooms will occur. Just like with alkalinity (low alkalinity = no bloom) as alkalinity is the limiting factor. You can add all the N and/or P you want and still not get a bloom.

What is needed is the right ratio of N & P and good alkalinity plus the right plankton species present. In providing advice I try to never let perfect be the enemy of improving the existing situation. The question here is - if you have non/minimally productive waters (no/low plankton bloom) do you accept the situation or try to improve things using available tools ? Learning to make optimal use (not no use) of the tools is what Dave's article is about.

Last edited by ewest; 06/27/19 12:37 PM.